Pluto-Charon perihelion

For 20 years (or 8%) of its 248-year orbit around the Sun, the dwarf planet Pluto is slightly closer to the Sun than Neptune. But even here at its perihelion, light from the Sun still takes 4 hours, 6 minutes to reach Pluto.​At the scale of this solar system diagram, the diameter of Pluto is about the same as two grains of salt. Its largest moon, Charon, is about the size of a single grain of salt, at a distance of only about 3 millimeters from Pluto. But technically, Charon does not orbit Pluto. Rather, Pluto and Charon orbit each other around a common barycenter (or center of mass) which lies between the two objects. For this reason, some astronomers classify Pluto and Charon as a binary system. The only close-up images of Pluto and its moons were taken by the New Horizons spacecraft, during its 2015 flyby.

The Pluto-Charon image on this page is a montage of photos taken in 2015 by the New Horizons probe, and is courtesy of NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.